Lipase: Difference between revisions

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== '''Colipase Coenzyme''' ==

Lipase is activated by colipase, a coenzyme that binds to the C-terminal, non-catalytic domain of lipase. Colipase must be present for activation of lipase and acts as a bridge between lipase and the lipid. When colipase binds, active lipase is stabilized for the hydrophobic interaction with triacylglycerides <ref>Fundamentals of Biochemistry...</ref>. Without colipase present, the accumulation of amphiphiles at the oil/water interface in the duodenum would prevent pancreatic lipase from binding. <ref>Crandall,W., Lowe, M. "Colipase Residues Glu64 and Arg65 Are Essential for Normal Lipase-mediated Fat Digestion in the Presence of Bile Salt Micelles" Journal of Biological Chemistry, 2001, (276) 12505-12512</ref>. Colipase is 10 kDa protein, secreted by the pancreas in its inactive form, which must be activated by trypsin before interacting with lipase. Colipase is a small protein cofactor with 5 conserved <scene name='Lipase/Colipase/3'>disulfide bonds</scene> (shown in yellow) <ref>"Colipase". Wikipedia: The Free Encyclopedia. 5 July 2011 [http://en.wikipedia.org/wiki/Colipase]</ref>, and 2 <scene name='Lipase/Colipase/4'>surfaces</scene>- a hydrophilic surface (site of lipase C-terminal interaction- shown in blue) and a hydrophobic surface (contains multiple hydrophobic loops to bridge the lipid- shown in white)<ref>"Colipase Residues..."</ref>. Colipase and lipase <scene name='Lipase/Contacts/2'>contacts</scene>are opposite of the active site on the C-terminal (contacts are regions of pink and yellow, with water molecules shown in darker blue). The enzymes are bound by polar interactions such as <scene name='Lipase/Salt_bridges/2'>salt bridges</scene>, <scene name='Lipase/Hphobic_interactions/1'>hydrophobic interactions</scene> and <scene name='Lipase/Hydrogen_bonds_non_water/1'>hydrogen bonds</scene> <ref>van Tilbeurgh H, etc."Structure of the pancreatic lipase-procolipase complex", 1992 Sep 10;359(6391):159-62. PMID:1522902.[http://www.proteopedia.org/wiki/index.php/1n8s]</ref>.

Lipase is activated by colipase, a coenzyme that binds to the C-terminal, non-catalytic domain of lipase. Colipase must be present for activation of lipase and acts as a bridge between lipase and the lipid. When colipase binds, active lipase is stabilized for the hydrophobic interaction with triacylglycerides <ref>Fundamentals of Biochemistry...</ref>. Without colipase present, the accumulation of amphiphiles at the oil/water interface in the duodenum would prevent pancreatic lipase from binding to its substrate. <ref>Crandall,W., Lowe, M. "Colipase Residues Glu64 and Arg65 Are Essential for Normal Lipase-mediated Fat Digestion in the Presence of Bile Salt Micelles" Journal of Biological Chemistry, 2001, (276) 12505-12512</ref>. Colipase is 10 kDa protein, secreted by the pancreas in its inactive form, which must be activated by trypsin before interacting with lipase. Colipase is a small protein cofactor with 5 conserved <scene name='Lipase/Colipase/3'>disulfide bonds</scene> (shown in yellow) <ref>"Colipase". Wikipedia: The Free Encyclopedia. 5 July 2011 [http://en.wikipedia.org/wiki/Colipase]</ref>, and 2 <scene name='Lipase/Colipase/4'>surfaces</scene>- a hydrophilic surface (site of lipase C-terminal interaction- shown in blue) and a hydrophobic surface (contains multiple hydrophobic loops to bridge the lipid- shown in white)<ref>"Colipase Residues..."</ref>. Colipase and lipase <scene name='Lipase/Contacts/2'>contacts</scene>are opposite of the active site on the C-terminal (contacts are regions of pink and yellow, with water molecules shown in darker blue). The enzymes are bound by polar interactions such as <scene name='Lipase/Salt_bridges/2'>salt bridges</scene>, <scene name='Lipase/Hphobic_interactions/1'>hydrophobic interactions</scene> and <scene name='Lipase/Hydrogen_bonds_non_water/1'>hydrogen bonds</scene> <ref>van Tilbeurgh H, etc."Structure of the pancreatic lipase-procolipase complex", 1992 Sep 10;359(6391):159-62. PMID:1522902.[http://www.proteopedia.org/wiki/index.php/1n8s]</ref>.

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Revision as of 03:08, 13 April 2012 view source Katelyn Clark (talk \| contribs) 9 edits No edit summary ← Older edit		Revision as of 03:09, 13 April 2012 view source Katelyn Clark (talk \| contribs) 9 edits No edit summary Newer edit →
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	== '''Colipase Coenzyme''' ==		== '''Colipase Coenzyme''' ==
	Lipase is activated by colipase, a coenzyme that binds to the C-terminal, non-catalytic domain of lipase. Colipase must be present for activation of lipase and acts as a bridge between lipase and the lipid. When colipase binds, active lipase is stabilized for the hydrophobic interaction with triacylglycerides <ref>Fundamentals of Biochemistry...</ref>. Without colipase present, the accumulation of amphiphiles at the oil/water interface in the duodenum would prevent pancreatic lipase from binding. <ref>Crandall,W., Lowe, M. "Colipase Residues Glu64 and Arg65 Are Essential for Normal Lipase-mediated Fat Digestion in the Presence of Bile Salt Micelles" Journal of Biological Chemistry, 2001, (276) 12505-12512</ref>. Colipase is 10 kDa protein, secreted by the pancreas in its inactive form, which must be activated by trypsin before interacting with lipase. Colipase is a small protein cofactor with 5 conserved <scene name='Lipase/Colipase/3'>disulfide bonds</scene> (shown in yellow) <ref>"Colipase". Wikipedia: The Free Encyclopedia. 5 July 2011 [http://en.wikipedia.org/wiki/Colipase]</ref>, and 2 <scene name='Lipase/Colipase/4'>surfaces</scene>- a hydrophilic surface (site of lipase C-terminal interaction- shown in blue) and a hydrophobic surface (contains multiple hydrophobic loops to bridge the lipid- shown in white)<ref>"Colipase Residues..."</ref>. Colipase and lipase <scene name='Lipase/Contacts/2'>contacts</scene>are opposite of the active site on the C-terminal (contacts are regions of pink and yellow, with water molecules shown in darker blue). The enzymes are bound by polar interactions such as <scene name='Lipase/Salt_bridges/2'>salt bridges</scene>, <scene name='Lipase/Hphobic_interactions/1'>hydrophobic interactions</scene> and <scene name='Lipase/Hydrogen_bonds_non_water/1'>hydrogen bonds</scene> <ref>van Tilbeurgh H, etc."Structure of the pancreatic lipase-procolipase complex", 1992 Sep 10;359(6391):159-62. PMID:1522902.[http://www.proteopedia.org/wiki/index.php/1n8s]</ref>.		Lipase is activated by colipase, a coenzyme that binds to the C-terminal, non-catalytic domain of lipase. Colipase must be present for activation of lipase and acts as a bridge between lipase and the lipid. When colipase binds, active lipase is stabilized for the hydrophobic interaction with triacylglycerides <ref>Fundamentals of Biochemistry...</ref>. Without colipase present, the accumulation of amphiphiles at the oil/water interface in the duodenum would prevent pancreatic lipase from binding to its substrate. <ref>Crandall,W., Lowe, M. "Colipase Residues Glu64 and Arg65 Are Essential for Normal Lipase-mediated Fat Digestion in the Presence of Bile Salt Micelles" Journal of Biological Chemistry, 2001, (276) 12505-12512</ref>. Colipase is 10 kDa protein, secreted by the pancreas in its inactive form, which must be activated by trypsin before interacting with lipase. Colipase is a small protein cofactor with 5 conserved <scene name='Lipase/Colipase/3'>disulfide bonds</scene> (shown in yellow) <ref>"Colipase". Wikipedia: The Free Encyclopedia. 5 July 2011 [http://en.wikipedia.org/wiki/Colipase]</ref>, and 2 <scene name='Lipase/Colipase/4'>surfaces</scene>- a hydrophilic surface (site of lipase C-terminal interaction- shown in blue) and a hydrophobic surface (contains multiple hydrophobic loops to bridge the lipid- shown in white)<ref>"Colipase Residues..."</ref>. Colipase and lipase <scene name='Lipase/Contacts/2'>contacts</scene>are opposite of the active site on the C-terminal (contacts are regions of pink and yellow, with water molecules shown in darker blue). The enzymes are bound by polar interactions such as <scene name='Lipase/Salt_bridges/2'>salt bridges</scene>, <scene name='Lipase/Hphobic_interactions/1'>hydrophobic interactions</scene> and <scene name='Lipase/Hydrogen_bonds_non_water/1'>hydrogen bonds</scene> <ref>van Tilbeurgh H, etc."Structure of the pancreatic lipase-procolipase complex", 1992 Sep 10;359(6391):159-62. PMID:1522902.[http://www.proteopedia.org/wiki/index.php/1n8s]</ref>.